Drawbench mechanism



April 28, 1931. N. H. cox 1,802,903

DRAW BENCH MECHANISM- Filed June 19, 1925 2 Sheets-Sheet 1 II II IM llllllllllllli lllllll April 28, 1931. NH OX Q 1,802,908

DRAW BENCH MECHANISM Filed June 19, 1925 2 Sheets-Sheet 2 amvemtoz Patented Apr. 28, 1931 warren starts 1 tsezscs PATENT GFFECE NATHAN HADLEY CCX, Cl NAUGATUCK, CONNECTICUT, ASSIGNOE TO SCOVILL IEANU- FACT'URING COMPANY, 01 WATERBURY, CONNECTICUT, A CORPORATION OF CON N ECTICUT DRAWB ENCH Application filed June 19,

This invention relates to draw bench mechanisms.

In draw bench mechanisms as now known, a carriage having a work-gripping device travels back and forth on a track which eX- tends away from the draw die. Below the track is the top strand of a continuouslydriven, endless chain. The carriage has a pivoted hook which is hooked into a link of the chain to cause the carriage'to be drawn by the chain away from the die. When a workpiece, such as a rod or tube, is grippedby the gripping device and the hook is hooked into the chain to be moved thereby, the work is drawn through the die. On the hook is a counter weight which is raised when the hook is hooked into the chain and so tends to raise the hook away from the chain. During the drawing operation this tendency is resisted by the tension on the hook. As soon, however, as the trailing end of the workpiece emerges from the die this tension is releasedand the weight can drop, thus swinging the hook out of engagement with the chain, so that the carriage is nolonger advanced on its drawing stroke. he carriage is then returned to initial position. A new workpiece being positioned with respect to the jaws of the workgripping device, an operator manually swings the combined hook and counter weight to raise the weight and lower the hook again into engagement with chain for the next draw.

It is one of the principal objects of the present invention to provide a draw bench mechanism that makes possible a more economical operation than that of mechanisms heretofore known. More particularly it is an object of the invention to provide a draw bench mechanism that eliminates the manual placement of the hook and other manual acts and renders the operation more automatic. 7

With these general objects in view the invention consists in the features, combinations, details of construction and arrangements of parts which will be first described in connection with the accompanying drawings and then more particularly pointed out. 1

In the drawings Figure 1 is a viewin side elevation, with parts in secti'on,of a draw bench mechanism .rod or tube 17 is to be drawn.

MECHANISM 1925. Serial No. 38,128.

constructed in accordance with the invention Figure 2 is a plan view of part of the same, with parts in section, looking in the direction of the arrow 2 of Fig. 1;. V

Figure 3 is a similar view looking in the direction of thearrow 3 of Fig. 1;

Figure 4 is an enlarged end view looking in the direction of arrow at of Fig. 1;

Figure 5 is a view (enlarged) in side elevation, with parts in section, of the carriage and associated parts at the initial position; and,

Figure 6 is a similar view of the carriage at the end of 1ts outward travel.

Referring to the drawings, the draw bench illustrated as an example has a framework 11- track. As shown, this chain is driven from a'sprocket 19 and at the die end of the bench passes over an idler sprocket 20. The sprocket '19 is driven as later described.

The invention in its entirety includes a carriage hook'and means whereby the hook is automatically removed from the chain at the end of a drawing operation and automaticab ly hooked into the chain at the start of the next operation. This may be accomplished, I

for example, by means of aweighted arm associated with the hook to raise the hook out of the chainand means for raising the weight whereby the hook again drops into the chain. Although capable of various constructions, in that here shown as an example, pivoted in the carriage 14 is a downwardly facing hook 25 adapted to hook into a chain link, in the manner illustrated in Fig. 5 When the hook makes such engagement with the chain, the carriage is drawn in the direction of the arrow (Fig. 5) namely, away from the draw die.

Associated with the hook an elbowshaped arm 26 carrying at its outer end an adjustably mounted weight 27. The weighted arm 26 is separate from the book but is pivoted on the same stud 28 on which hook 25 is pivoted. The hook 25 and the arm 26 are provided with cooperating parts whereby the arm in dropping exerts a lifting action on the hook to raise the same and whereby the hook is dropped when the arm swings up. To this end, as here shown as an example, the inner or pivoted end of the hook is bifurcated to receive the end of the arm 26 (Fig. 6). On the end of arm 26 is an upwardly facing oblique lug 29 and the hook 25 has a downwardly facing oblique abutment surface 30 for engagement by the lug 29. l/Vhenthe weighted arm 26 is in raised position and the hook 25 is hooked into the chain, the lug 29 engages the abutment 30 and the tendency of the weight to drop tends to raise the hook by the leverage of lug 29 on the hook. That is, the arm 26 is now in the nature of a counter weight for the hook. The tendency of the arm 26 to. drop is resisted during the drawing operation by the tension between the chain and the hook. This tension continues until the trailing end of the rod or tube emerges from the die. When this occurs the tension is relieved, the weighted arm 26 drops, and the engagement of the lug causes the hook to swing upwardly, out of engagement with the chain. Fig. 6 shows the carriage at the end of a drawing stroke with the weighted arm in its dropped position and the hook raised. Due to this disengagement of the hook from the chain, the carriage is no longer moved outwardly, and may, upon removal of the workpiece, be returned to initial position.

lVhile the means for raising the weighted arm may vary, as here shown as an example, on the frame is a bracket 33 carrying a cam piece 31 having an oblique cam track or face 34. This cam piece is adjustably secured to the bracket by a bolt and slot connection 32, 32. On the arm 26 is a lug 35 carrying a cam roller 36 positioned to ride up cam track 34 as the carriage idly returns to initial position. As the roller rides up the cam track the weighted arm is raised, thus withdrawing lug 29 from abutment surface 30. This frees the hook and permits it to drop by its own weight into engagement with the chain. The parts are now in some such position as illustrated in Fig. 5 with the lug 29 and abutment surface 30 in or nearly in contactingengagement. As the carriage advances under the drag of the chain and hook the roller 36 is withdrawn from cam 34. Should the lug and abutment be slightly separated after the drop of the hook, the arm 26 can swing down slightly, as the roller rides down the cam, to move the lug up to the abutment. In any event, after the roller has withdrawn from the cam track, the weighted arm is again in its raised posidisconnected automatically. Although capable of various constructions, in that here shown as an example, secured to a lug 38 on a side bar 39 on the carriage is an endless conveyor cord or cable 40. This cord is driven by a drive pulley 41 loosely mounted on a shaft 42. Shaft 42 is continuously rotated by a gear 43 operated by a pinion 44 to which power may be applied in any suitable manner. On the shaft 42 is also a pinion 45 driving a gear 46 on a shaft 47 which drives the sprocket 19 for the chain.

Associated with the pulley 41 is a clutch 48 operated by a clutch lever 49 mounted on a rock shaft 50. On the rock shaft is a rocker arm 51 operated by a connecting link 52. At

the die end of the bench, the link 52 is con nected to a rocker arm 53 on a rock shaft 54 operated by a treadle 55. At the completion of a drawing operation an operator depresses treadle 55 thereby operating the clutch to con nect pulley 41 to the shaft 42. This causes the cord conveyor, running in the direction of the arrows (Fig. 1), to return the carriage to initial position.

While the automatic means for disconnecting the clutch at the end of the idle return of the carriage may vary, in the embodiment here illustrated asan example, on the rock shaft 54 is an arm having an adjustable stop pin 61, a spring 62 tending to hold the parts in normal position, i. e. with the clutch out. Cooperating with the stop pin is a stop plate 63 pivoted in a bracket 64, a spring 65 tending to tilt the plate downward. When the treadle is operated as above described, to connect the clutch, the arm 60 swings back permitting the stop plate 63 to move down. This places the plate in the path of the stop pin 61 so that the arm 60 cannot return under the force of its spring. As a result, the clutch is held in, even though the operator releases the treadle. To remove the stop plate, as

here shown as an example, secured to the latter is a lifting cord or link 66 attached to a lever 67 located to be engaged by a trip lug 68 on the bar-39. Vhen the carriage'reaches initial position, the lug 68 tilts lever 67 and causes link 66 to raise plate 63 against its spring. This permits spring 62 to swing back arm 60, which rocks shaft 54 reversely and causes-the clutch, through link 52, to be thrown out. lVhen the carriage moves out-- wardly again, lever 67 is free to return. to its former position under force of a return spring 69.

In operation, assuming the carriage to be approaching the end of a drawing strgke, the

ment 30 on the hook. The tendency of the arm 26 to drop tends to lift the hook out of the chain and this occurs when the tension on the hook is relieved by the trading end of the workpiece emerging from the die. This lifting of the hook automatically disconnects the carriage from the conveyor chain, thus ending the carriage movement. .The operator now depresses treadle 55 and clutches pulley 41 to shaft 42 by the connections de scribed. Upon actuation of the treadle, which displaces arm against its spring, stop plate 63 drops into the path of stop pin 61 and holds the parts in clutching position so that the operator may release the treadle. Then the pulley 41 is thus clutched to the shaft 42, the endless conveyor cord 40 is actuated to drag the carriage back toward the die end of the bench. During this idle return the arm 26 is down thus holding hook 25 raised. As the carriage reaches the end of its idle return, the trip lug 68 strikes lever 67 and swings the same to cause cord or link 66 to lift stop plate 63 and remove it from the path of pin 61. This permits spring 62 to swing back rocker arm 60, thus reversing rocking shaft 54 and reversely actuating link 52 to throw out the clutch so that the return conveyor cord is no longer actuated.

Meanwhile, as the carriage approaches the end of its idle return, the roller 36 rides up cam track 34 thus elevating weighted arm 26. This withdraws lug 29 from the abutment 30 on the hook 25 and permits the hook to drop automatically into engagement with the chain. \Vhen the hook has effected such engagement the tongs 15 are caused to grip a new workpiece, which previously the operator has placed in the die, so that as soon as the hook makes its engagement with the chain, the carriage starts forward again on the next draw.

As the carriage starts outwardly the roller 36 leaves cam 34 and the weighted arm, as

above described, is again in its counter weight relation with respect to the hook. Also, as the carriage starts its drawing stroke trip lug 68 recedes from lever 67 which returns to its former position under force of its spring 69 and releases the pull on cord 66 so that stop plate 63 is again free to drop as soon as arm 60 and its pin 61 are again displaced. During the drawing movement of the carriage the return cord 40 merely travels idly over its pulleys, in the reverse direction indicated by the broken-line arrows of Fig. 1.

What I claim is:

1. In a draw bench mechanism, and in combination, a draw die, a carriage movable away from and toward the draw die, work-gripping means on the carriage, an endless conveyor, a hook pivoted on the carriage to tend to drop by gravity into hooking engagement withthe conveyor,'the carriage being drawn away from the die upon such engagement, lifting means engaging said hook and norfmally tending to raise said hook out of engagement with the conveyor and operable to so raise it upon relief of the tension when the trailing end of the work emerges from the die, said hook being freely movable independently of said lifting means and means for counteracting said lifting means upon the return idlestroke of the carriage, whereby the hook is free to drop by gravity into engagement with the conveyor.

2. In a draw bench mechanism, and in combination, a draw die, a carriage movable away from and toward the draw die, workgripping means on the carriage, an endless conveyor, a hook pivoted onv the carriage to tend to drop by gravity into hooking engagement with the conveyor, the carriage being drawn awayfrom the die upon such engagement, a counter weight on the carriage engaging the hook so as normally to tend to raise the hook by the dropping of the weight, said hook being freely movable independently of said weight, and means for raising said weight upon the return idle stroke of the car- ..riage to effect an automatic gravity drop of the hook into hooked connection with the conveyor. a

3. In a draw bench mechanism, and in combination, a draw die, a carriage movable away from and toward the draw die, work-gripping means on the carriage, an endless conveyor, a hook pivoted on the carriage to tend; to drop by gravity into hooking engagement with the conveyor, the carriage being drawn away from the die upon such engagement, a weighted arm pivotally mounted on the carriage and having a leverage-portion for en-.-

gaging a portion of the hook thereby to raise the hook as the weighted arm drops, and .means operable upon theidle return of the carriage for raising said weightedarm, thereby to permit the hook to drop by gravity.

4. In a draw bench mechanism, and in combination, a draw die, a carriagemovable away from and toward the draw die, work-gripping means on the carriage, an endless conveyor, a hook pivot-ed on the carriage to tend to drop bygravityintohooking engagement with the conveyor, the carriage being drawn away from the die upon such engagement, a weighted arm pivoted coaxially with the hook and having a lug for engaging a portion of the hook to raise the hook as the weighted arm drops, and means operable upon the idle return of the carriage for raising said weighted arm, thereby to permit the hook to drop by gravity.

5. In a draw bench mechanism, and in combination, a draw die, a carriage movable away from and toward the draw die, work-gripping means on the carriage, an endless conveyor, a hook pivoted on the carriage to tend to drop by gravity into hooking engagement with the conveyor, the carriage being drawn away from the die upon such engagement, a counter weight on the carriage engaging the hook so as normally to tend to raise the hook by the dropping of the weight, said hook being freely movable independently of said weight, a cam roller on said counter weight, and cam means located adjacent the draw die for engagement by the roller, thereby to cause the counter weight to be raised on the idle return of the carriage and efiect an automatic gravity drop of the hook into hooked connection with the conveyor.

6. In a draw bench mechanism, and in combination, a draw die, a carriage movable away from and toward the draw die, work-gripping meanson the carriage, an endless conveyor, a hook pivoted on the carriage to tend to drop by gravity into hooking engagement with the conveyor, the carriage being drawn away from the die upon such engagement, a weighted arm pivotally mounted on the carriage and having a leverage portion for engaging a portion of the hook thereby to raise the hook as the weight drops, a cam roller on the weighted arm, and an inclined cam element located adjacent the draw die for engagement by said roller on the idle return of the carriage to cause the weighted arm to be raised, thereby to permit the hook to drop by gravity.

7. In a draw bench mechanism, and in combination, a draw die, a carriage movable away from and toward the draw die, work-gripping means on the carriage, an endless conveyor, a hook pivoted on the carriage to tend to drop by gravity into hooking engagement with the conveyor, the carriage being drawn away from the die upon such engagement, a counter weight pivotally mounted in the carriage, a leverage lug on said counter weight for engaging a portion of the hook in a manner to raise the hook when the counter weight drops, and means for causing said lug to be withdrawn from the hook upon the idle return of the carriage, thereby to permit the hook to drop by gravlty.

In testimony whereof, I have hereunto set my hand.

N. HADLEY COX. 

